Measuring Temperature and Soil Properties for Finite Element Model Verification

Abstract and project information last updated: 1 March 2011. Project updates are dated below.

A woman uses two wrenches to afix a pipe fitting on 2inch diameter conduit.

Credit: Christine McCabe

Margaret Darrow prepares some field equipment at the site of the soil sampling station along the Richardson Highway.

AUTC
Project
Number
RR08.11
Principal
Investigator
Margaret Darrow (UAF)
margaret.darrow@alaska.edu
Funding
Agency

US Department of Transportation (RITA)

Alaska Department of Transportation & Public Facilities

Project
Budget
100000
Start
Date
1 July 2008
Estimated
End Date
30 June 2010

Abstract

In recent years, ADOT&PF personnel have used TEMP/W, a commercially available two-dimensional finite element program, to conduct thermal modeling of various embankment configurations in an effort to reduce the thawing of ice-rich permafrost through thermally stable embankment designs. This modeling was done with historic air temperature data and input parameters derived from the literature, since site-specific data is typically not available. The overall goal of this study was to verify the thermal modeling results produced by TEMP/W. Temperatures and soil properties were measured at two different sites underlain by permafrost in Interior and Southcentral Alaska. A sensitivity analysis of certain input parameters was conducted on models of each site. Analysis indicates that the most critical input parameter is air temperature. While historic air temperature data provided an approximation of the regional climate, this data produced model results that were too cold by several degrees. Using air temperatures measured at each site resulted in models that closely matched the measured soil temperatures, and either matched or overestimated active layer depths. Using the overestimated active layer depth for design purposes would result in a more conservative embankment construction, which is a favorable approach if a warming climate is considered.

Final Report

INE/AUTC RR08.11
25 Feb 2012

Measuring Temperature and Soil Properties for Finite Element Model Verification
Margaret Darrow (UAF)
RR08.11.Darrow_FINAL_TEMPW_report_7_28_2010.pdf

Related Project Activity

21 October 2010

Darrow Presents Project Brief

by Joel Bailey

Margaret Darrow presented “Measurement of Temperature and Soil Properties for Finite Element Model Verification” at a GoTo meeting. The slide summary is available in PDF: temp_and_soil_measures_darrow.pdf.